I am assuming that by pneumatic, you are talking about liquid adhesive you can spray through a paint gun. You should be able to purchase this type of adhesive from the local auto parts store. It should come in gallons and half gallons.

But for the average person, the aerosol adhesive will work fine. The cost for one or two headliner installations will probably be much less than buying everything they need to be able to atomize the liquid type. For the doityourselfer, the 20 oz spray can adhesive would be the best bet.